A typical hydraulic power steering system for automotive vehicles includes a steering gear with housing, steering shaft and steering rack, a hydraulic cylinder coupled to said steering rack, a pump and a steering valve which controls the pressure fluid flow from the pump to the hydraulic cylinder in dependence on the actuation of steering. Steering systems of the like are fitted to many passenger vehicles, particularly to more expensive cars. Usually, the single component parts are mounted one after the other directly into the vehicle body on the body assembly line. After the assembly, the system is filled with pressure fluid, vented and tested. If any defect is found, the defective parts must be disassembled and replaced with great effort. Additionally, it is expensive to warehouse the various components at the vehicle maker's premises.
Another disadvantage of the known power steering systems is that, once the automotive vehicle is used up or junked, they can be recycled only by entailing great expenditure in time and cost. In this case, took, all elements would have to be disassembled one by one from the vehicle, and the system within the vehicle would have to be previously discharged. This shortcoming is particularly important in view of forthcoming legal regulations concerning the re-cycling of old cars and their component parts.